The invention lies in the field of mechanics, in particular precision mechanics, and may be advantageously applied to the medical field.
However, independently of the application in the medial sector, applications in other fields may be envisaged, where a fluid pump is to be operated under restricted spatial conditions or at poorly accessible locations.
This is particularly the case with minimal-invasive medical technology, where often medical instruments or apparatus must be brought to the location of application, for example through blood vessels, with an as gentle as possible treatment of the patient. It is particularly in this context that the application of blood pumps in combination with catheters has become known, which for example may be introduced into a heart chamber whilst supporting the heart pumping activity.
Since a certain size is necessary for an optimised performance of such a pump, which however is limited by the diameter of the large blood vessels of the body which end in the heart, it is already known to use fluid pumps which are changeable in their radius for this purpose, which may be expanded after introduction into the heart chamber.
This is made possible either by way of special mechanisms, which permit an actuation of a spanning mechanism of the pump by way of a catheter, as is known for example from the US patent document US 2008/0103591 or WO 03/103745, or by way of the use of so-called memory materials, which may assume different shapes when changing the temperature of the surroundings, and may be brought into the desired end shape by way of temperature change.
An alternative solution is known from U.S. Pat. No. 7,393,181 B2, with which flexible rotor blades may be applied onto a hub and be reversibly deformable in a manner such that they are automatically set up on pump operation.
However, tight limits are placed on the expansion ability of such pumps due to the necessity of accommodating a drive shaft as well as a rotor and pump housing within a small diameter.